donrhummy

Has anyone here used a Stages power meter?
How is the accuracy?
battery life?
consistency?
does it connect well to a Garmin?

How does it compare to any other power meters you've used? Which one would you recommend? (if price was important?)

RChung

Well, here's one guy:



and here's another, different guy:

KantoBoy

I was in a dilemma between Stages and Power2Max and I ended up with P2M.

- for the price,it was almost the same for an Ultegra Crank vs Rotor3D crank. I got a sweet deal on Cyber Monday (Rotor3D+BOR rings+optional deal on BB). I was wondering on why Stages wasn't offering anything on that weekend.

- this is assuming you're paying for the 2 year warranty on Stages. I THINK 1 year warranty on something that expensive is unfair. P2M is also located in Canada so warranty would be dealt easier.

- No need to worry about the left leg only power

- wait time

I guess if you already have their cranks (Stages), then getting the arm only would obviously save you money.

*I'm not a weight weenie.

robbyville

I have one, I can't comment on accuracy since it's my first power meter so I don't have anything to compare to, but I figure I have my baseline via Stages and continue to use the same unit ergo it's accurate for my usage and training, same goes for consistency.

They shipped with 2 batteries, I'm still on my first one, I've had the unit since mid-summer, did the firmware update yesterday, seems like battery is still fine. I have about 1500 miles on it so far.

I have it paired to a Garmin 500, instant no problems ever even with initial pairing. I also use TrainerRoad, the Garmin Ant+ stick picks it up no problem either when I'm on the rollers or trainer.

donrhummy

thanks for the graphs, but ,i read his article and one thing he stressed was that it was only one person's experience so I'm looking for other experiences.

donrhummy

thanks! that's a great review and helps. have you put the data into a computer to check for weird spikes or loss of data during rides?

robbyville

I put every workout into training peaks along with strava. I'm still fairly new to training with power so not sure that I can truly give an educated opinion since I'm still learning to analyze the data.

Still, I've seen no inconsistencies or loss of info, everything seems consistent with a person on a regimen (no awkward or huge jumps in the numbers). Not really sure if in the best to speak to this, the unit has definitely been good for me and for my needs.

RChung

Those are two different guys. The first is (perhaps obviously) Ray; the other is a different guy. The first graph shows inconsistent measurement at high power, the other shows inconsistent measurement at low power. I've *never* seen a case where bilateral asymmetry was constant across the power range. Whether that's important to you depends on what you're hoping to use a power meter for, and what your situation is. That's a different question than whether bilateral asymmetry is rare or common, or whether it varies (the answer to that is it's common, and it does).

Silvercivic27

Sounds like you're not a fan of stages. Can you give specific examples of where the stages would not be as good as let's say a Quarq riken since a lot of people I know are really trying to choose between those two? I myself use Quarq Elsas because at the time I bought them, my sense was to just go with the "tried and true". For example, I get the sense that stages may not be as good for measuring sprint efforts, or maybe even recovery or endurance efforts, where the L-R discrepancy would be more pronounced, and in the case of the sprit effort, there's less data points so the averaging changes things more due to the short time. Seems like it wouldn't be bad for a time trial, where L-R power is more likely to be more even. You seem like a smart, well informed person. Thx.

RChung

Um, You talking to me?

I'm a fan of the Stages for certain things but not for everything. When I look at power meters I look at the quality of the data they produce, but I understand that not every use of a power meter requires equivalent levels of data quality. For example, training (especially for those just starting out) is perhaps the least demanding use of a power meter; drag estimation (both for rolling and aerodynamic drag) is one of the most demanding. I thought the differences and ideal uses were clear from the reviews but I'm learning that they weren't. When you first start out with structured training you can make big improvements. During this period almost anything you use works. Eventually you hit a plateau and at that point you really want to know if that small difference your power meter recorded on today's ride was real or illusory. Some people hit that plateau sooner rather than later but some people never really get into structured cycle training so they bounce up and down in cycling fitness like a wave rather than reach a plateau. That's why I say training is one of the least demanding uses of a power meter. So, for people starting out or who started long ago but haven't really gotten into structured training the Stages can be okay. Whether it's worth the cost compared to other offerings is up to your specific needs and checkbook balance, not me. I just look at the data to see what the differences are. For this I'm pretty good: that's why Ray Maker and others have come to me to help them work out their test protocols and procedures before their tests and to help them with the data analysis after. When Ray's initial review came out, Stages initially denied that they had any problem and claimed that my analysis was incorrect -- then they held their units back from release, released a firmware update to address the vibration problem, and also put a lower limit on what they said their cadence range was. That was a good outcome: the world got a better product because my analysis revealed something that everyone at Stages had previously overlooked. That was gratifying, and I want more, better, and cheaper power meters on the market -- why would I not? -- and they paid attention to my analysis so in this I *am* a fan of the Stages.

But, as I said above, there are some uses where the Stages hasn't yet shown that they can produce equivalent data quality. For Ray the Stages tends to underreport at high power levels. For the other guy whose data I showed the Stages underreports at low power levels. I've seen one guy with a U-shaped balance: his right-left balance is skewed at both low and high power but tends to be pretty close to even near his FTP. I've never seen anyone with "flat" balance across all power outputs or fatigue levels. If very high or very low power matters to you (and it won't to many) then any of these patterns should worry you. If you're trying to use a power meter to pace your ultra-endurance ride (and not everyone does) then that should worry you. If you do drag testing in the field (and not everyone does) then that should worry you. If you need to do pedal force/pedal speed analysis (and not everyone does) then that should worry you. If you're starting out with a power meter for the first time and all you want to do is train (and there are lots and lots of people in that boat) the Stages could be a fine gateway drug.

[Edited to add:] I do find it kinda amusing sometimes when people try to explain to me what Ray's reviews (or the reviews of others who've come to me) say.

simonaway427

I've been using one for about 2 months now. No issues with pairing to my Edge 500 or ANT+ USB stick on trainer road. I can't really compare it to any other power meter since this is my first experience with one.

The only thing I can say is that it reads about 20 watts higher than the Trainer Road Kinetic virtual power curve. I haven't experienced any dropouts or irregular data. My only wish is that there was an Android version of their app so I can update the firmware

robbyville

Probably one of the best, even keeled, explanations I've heard so far, thanks so much! My problem before is that on the thread in writing previous comments came across as snarky or maybe a little holier than thou, hence my defensiveness, my apologies if that was the case.

Silvercivic27

Thanks, RChung, Yes, I was talking to you, and if you don't mind, I'm going to continue asking questions, as I feel this thread stands to educate and help a lot of people.

I think you bring up great points. From what you're saying, I'm inferring that the stages isn't very good for analyzing, and therefore, working on your sprint (in particular), and maybe even 1 minute power or potentially even longer (like 3 minute). This will be important for people who race criteriums and road races, where the sprint and these additional time points are important. It's probably because the power drops off so fast, and in a non-linear fashion. That is very important to many people who are considering the Stages. I understand that there are many things to learn for a new power user, and that a Stages may be good enough for that (using the software, etc.), but if buyers are going to have remorse a year down the line because the thing they bought isn't as useful anymore, it's not a good thing. Then the Stages isn't such a good deal anymore.

That being said, I can't think of many people at all worrying about the other points you mentioned, except for people doing research, or people with injuries trying to do rehab, for example. I'm not sure how important L-R power imbalance is in practical real-life situations, unless you're only really measuring one side (like Stages). That's why I'm not sold on the necessity of measuring power in each leg like Vector. I think of it in my mind kind of like doing a bench press. One arm is always weaker than the other, but unless you're lifting a really heavy or really light weight, there isn't going to be much teetering and imbalance. That's kind of what the imbalance graphs are showing us, right? I think that just about all people who are near their FTP are going to be pretty even, because the legs will try to balance each other out, (like when doing bench presses) which in my mind makes Stages very useful for events near FTP like Time trials, and even most training, except obviously sprint training. Ultimately, though, just like the important thing is to get that barbell up there. The important thing in a sprint is to get to the line, and then L-R power imbalance doesn't seem to be all that critical (unless you go off the road or something, lol)

The whole idea of increased sampling increasing accuracy means something to me too, and so I have some buyers remorse that I even got Elsas. It makes me want SRM, especially with the new, more practical PowerControl display, and even the Pioneer system seems interesting. For me, though, the Elsa is good enough at least for now. At some point, the plateau, is you, not the fact that you're using this or that powermeter. Most people (myself included) don't understand all of these data well enough to analyze it thoroughly anyway. I guess that's the main reason why I have a coach telling me what to do. The problem is, garbage in, garbage out. If my coach gets garbage in, no good. If a stages gives you garbage in. . .

Sorry it seems like I have schizophrenia. There's just a lot to talk about.

robbyville

But if your data has always been on the same device wouldn't analysis still be consistent event if off in the actual numbers (ie if high level power has always been off then any increase would be relative), or is there no consistency in the inacurracies?

Silvercivic27

I would think that at least for sprint and short duration power measurement and analysis, as you say, there's no consistency. (Consistently inconsistent, lol)

RChung

Maybe, but lots of people aren't doing much analysis (or are doing a poor job of the analysis they do). The real issue is whether a particular buyer is one of the people for whom this kind of thing is a deal killer. That's why Ray's review (and Greg Kopecky's, and a few others) are so long and detailed -- not everyone has the same needs or checkbook balance or experience with power meters. I've said that in many ways training is the least demanding use for a power meter; comparing the average power for two power meters (or one power meter and an indoor trainer) is the least demanding test of data quality. What's important isn't how close two power meters read on average; what's important is knowing the conditions under which they differ and by how much. Once you know that you can figure out whether a particular purchase meets your particular needs. Most reviews never get to the "under what conditions and by how much" level. Those kinds of reviews are less helpful than they should be.

Depends on the kinds of analysis you're doing. NP (and measures that rely on NP, like TSS) depend on actual power values. NP is already a nonlinear estimator so adding in some extra unknown nonlinearity can be a pain. Likewise, CP/W' estimation (though I'm not a huge fan of CP/W' estimation) also depends on MMP at different durations. However, if you're just starting off with training this sort of problem tends to be less important than after you've been training for a while and you get closer to your real ability limit.

donrhummy

ok. I read the first graph as showing inconsistency at low time intervals, thinking it meant the stages couldn't create an accurate reading until it had many data points over a longer time.

I understand the problems with stages, what are your thoughts on the powertap g3? I mention that because it's approximately the same price)

RChung

Every power meter has strengths and weaknesses. For my particular needs the PT is ideal but for others with different needs it may not be, and I try not to think that just because something works for me that everyone else should do what I do. I tend to focus on data quality because most other people focus on features or price or usability but ignore data quality. From a data quality point of view, the most consistent products out there are the SRM and PT, with the Quarq and Power2Max and Vector just a smidge behind. The PT and SRM do have idiosyncrasies but they're known and relatively minor. Here's the interesting thing: both SRM and PT manufacture their own head units that are specifically designed to work with their power meters, while the other manufacturers rely on third party head units (a market which is dominated by Garmin). The Look Keo Power pedals also use a specific head unit (from Polar) but the data quality for that power meter is kinda iffy, so just having a dedicated head unit doesn't appear to be sufficient. I don't have a large enough sample size to make comments yet on the Rotor, or Panasonic, or others. I haven't looked at the data quality of the iBike for a while so I don't know where its current model stands (but previous models would have put it below the others in terms of data quality).

As it happens I use different crank lengths and chainrings on my road and TT bikes. Different crank lengths allowed a bigger improvement in aero drag than the difference between a "race wheel" and my PT wheel with a wheel cover -- so for me using the same cranks on my bikes is a bug, not a feature. But not everyone cares about drag estimation or has a TT bike so it would be silly for me to insist that everyone do what I do. If you just care about training and you don't care about the other stuff the Stages could be a reasonable choice. So could the PT.

thechemist

Some really good stuff in here, a must read for those looking into power meters.

donrhummy

In what aspect is the vector lacking?

Garmin also has their own: the 810. (I say only the 810 because that's the only one with the latest firmware that has updates for left-right differences and a few other Vector-specific features)

But are you saying that PowerTap with a Garmin computer is not as consistent and accurate?

This comment makes it sound as though PT and stages are equally good choices for someone only caring about training. But I thought (from your previous comments and the data/graphs) that it depends on the type of training for which power meter will offer accurate/consistent enough data?

RChung

See below

It appears so. The problem with the Garmin head units appears to be with a small lag in recording. It's easiest to see when you start up or stop: in those cases you can see that there are often a couple of seconds where speed is non-zero (or zero) but power is zero (or non-zero). However, the issue still appears to apply even when you're not starting up or stopping; that's just when it's easiest to see. In the grand scheme of things this is a tiny problem but if you're trying to analyze pedal force/pedal speed it can be a pain in the butt. We know it's a problem with the head unit because if yoiu look at the data from the same PT hub being received by a Cervo (Little Yellow Computer) and a Garmin the data differ slightly. [Edited to add:] I haven't tested the same PT with a Cervo and a Joule so I don't know if this is an issue with the Joule -- I only know it shows up with the Garmin head units.

You're right, it does depend on the type of training you do. I was speaking about training in general rather than specific types of training. Every power meter has idiosyncrasies but sometimes these idiosyncrasies affect the data stream but not in a particularly fatal way as long as you know about it.

donrhummy

So am I correct that this means it will be useless on quick sprint intervals (e.g. 10 seconds on, 20 seconds off)? I thought I read (in DCRainmaker's piece) that some of the power meters recorded 2-3 times a second even with the Garmin head unit. Is this incorrect?

Is this a limitation of Ant+ or of Garmin's head units?

RChung

It depends on whether you're trying to do Tabatas at a particular targeted power (and you probably shouldn't be). Tabatas are done "full on" for a particular interval of time. I suppose if you were doing a more exotic version of Tabatas it could have an effect.

The ANT+ standard broadcasts at 4Hz but most ANT+ head units choose to record one signal per second from the four they receive. They typically don't keep all four and then average them, they typically just ignore three of the signals and keep one. Which one they keep seems to vary. We've noticed differences between different Garmin units (like, the 500, the 510, the 800, and the 810). The ANT+ standard does have some limitations but I think this is more about Garmin's implementation.

Am I making you sorry yet for asking these questions? This is why I generally give one sentence answers.

donrhummy

I meant it more for evaluating the data after the workout, not during the 10-second sprint. That would be impossible.


What about the 705? (I have that one)

Not even a little. In-depth, knowledgeable answers like yours are the reason I post on sites like this. Thank you for taking the time!

RChung

Hmmm. I haven't seen a 705 in at least a couple of years. I know that the 705's altimeter is a bit "steppy" but I don't remember whether the 705 had the "lag" problem.